Currently, the display technology has progressed from 2D display to 3D display. In order to meet various requirements of users, a 2D/3D display switch technique, which enables the display of an image in a 2D or 3D mode according to the users' requirements, has become a new trend for a stereo display device.
Parallax baffle 3D display is the most common 3D display technique at present, and FIG. 1 shows its structure and principle, where an array substrate 1 and a parallax baffle 2 are provided. The parallax baffle 2 is arranged in front of or behind the array substrate 1, and consists of nonopaque regions 21 and parallax barriers 22 arranged at a regular interval. Different images are viewed through the parallax barrier 2 by left and right eyes of a viewer, so the 3D image display is achieved.
Based on the above-mentioned 3D display principle, an active barrier is usually used in the prior art so as to implement the 2D/3D display switch. As shown in FIG. 2, the active barrier 3, as a liquid crystal panel with a twisted nematic (TN) mode, is arranged in front of a display unit and includes an upper substrate 31, a lower substrate 32, a first electrode 33, a second electrode 34 and a liquid crystal layer 35 arranged between the first electrode 33 and the second electrode 34. When the first electrode 33 is electrically connected to the second electrode 34, a slit grating structure, in which the nonopaque regions and the parallax barriers are arranged at a regular interval, is formed, so as to achieve the 3D display. When the first electrode 33 is not electrically connected to the second electrode 34, the light can be transmitted so as to achieve the 2D display.
However, the active barrier with the structure as shown in FIG. 2 is very expensive, and has thus become a major obstacle to marketing the display device with a 2D/3D display switch function.